The aims are to determine whether 6 months progressive graded treadmill training: 1) improves cardiovascular fitness levels and reduces the excessive energy demands of hemiparetic gait, as defined by oxygen consumption levels based on open circuit spirometry during peak and submaximal exercise ambulation tasks; 2) increases free living physical activity measured by portable kinematic recording devices and quantitative in vivo determination of energy expenditure using stable isotopes; and, 3) improves the cardiovascular-metabolic risk factor profile including measures of key endogenous fibrinolysis regulatory enzymes [plasma tissue plasminogen activator (t-PA) and its main circulating inhibitor (PAI-1)], fasting lipoprotein lipid profiles, blood pressure, and oral glucose tolerance and insulin responses. Measurements of body composition at baseline and after training will further determine the effects of aerobic exercise training on muscle mass and central obesity.